Front view. BDP-S790 on top.

Both players have front & rear USB connectors.
Top view. BDP-S790 on top.

The BDP-S780 has 4 switches near the bottom of the front panel. The BDP-S790 has 4 sensing spots near the front of the top cover (I/O label at left end & 3 lighted patterns near the right end).
BDP-S790 on top. The finish of both models easily show dust specks.

BDP-S790 on top.

Only the BDP-S780 has component video out & a Control S jack. The S790 has 2 HDMI out vs 1 for the S780. Remaining rear connections are identical for both players.
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TA- E77ES E1000ESD N77ES F555ES
RM- AV3000 AX1400 (2)AX4000
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DVP- (3)NS999ES NS3100ES CX777ES
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MDS-JA20ES, TC-K717ES, DTC-690
Pioneer CLD-3090 Laserdisc